Dust boot tool

Abstract

A dust boot tool includes a shell, a piston, a valve and stretchable rods. The shell includes a chamber in communication with an inlet channel. Pressurized air enters the chamber via the inlet channel. The piston is movable in the chamber by the pressurized air, and includes a first section, a second section opposite to the first section, a vent in the first section in the vicinity of the inlet channel, and a conical internal face extending on the second section. The valve includes a portion movably inserted in the vent. Each of the stretchable rods includes a stretchable end for contact with a dust boot, an abutment end in contact with the conical internal face of the second section of the piston, and a pivotal portion formed between the stretchable end and the abutment end and pivotally connected to the shell.

The invention claimed is: 
     
       1. A dust boot tool comprising:
 a shell comprising an inlet channel and a chamber in communication with the inlet channel, wherein pressurized air enters the chamber via the inlet channel; 
 a piston movable in the chamber by the pressurized air and comprising a first section, a second section opposite to the first section, a vent in the first section in the vicinity of the inlet channel, and a conical internal face extending on the second section; 
 a valve comprising a portion movably inserted in the vent; and 
 stretchable rods each of which comprises a stretchable end for contact with a dust boot, an abutment end in contact with the conical internal face of the second section of the piston, and a pivotal portion formed between the stretchable end and the abutment end and pivotally connected to the shell. 
 
     
     
       2. The dust boot tool according to  claim 1 , wherein the shell comprises pairs of recesses evenly arranged around the chamber and slits each of which is located between the recesses of a corresponding pair, and each of the stretchable rods further comprises a pair of pivots formed on the pivotal portion and inserted in a corresponding pair of recesses while the pivotal portion is inserted in a corresponding one of the slits. 
     
     
       3. The dust boot tool according to  claim 2 , further comprising a cap connected to the shell to keep the pairs of pivots in the pairs of recesses. 
     
     
       4. The dust boot tool according to  claim 3 , wherein the cap comprises slits for receiving the pivotal portions of the stretchable rods and pairs of recesses for receiving the pairs of pivots of the stretchable rods. 
     
     
       5. The dust boot tool according to  claim 3 , wherein the cap comprises a disc-shaped portion connected to the shell and a cup-shaped portion in contact with the valve. 
     
     
       6. The dust boot tool according to  claim 5 , wherein the cap comprises a pushing element extending from the cap to abut against the valve. 
     
     
       7. The dust boot tool according to  claim 5 , further comprising a first elastic element compressed between the disc-shaped portion of the cap and the stretchable rods so that the stretchable rods are normally withdrawn by opening and closing. 
     
     
       8. The dust boot tool according to  claim 1 , further comprising a sealing ring located around the piston and in contact with a wall of the chamber. 
     
     
       9. The dust boot tool according to  claim 8 , wherein the piston comprises an annular groove for receiving the sealing ring. 
     
     
       10. The dust boot tool according to  claim 1 , further comprising:
 a first sealing ring inserted in the chamber; 
 a lining located on the first sealing ring; and 
 a retaining ring located on the lining and connected to the shell. 
 
     
     
       11. The dust boot tool according to  claim 10 , further comprising a second sealing ring located around the piston and in contact with an internal face of the lining. 
     
     
       12. The dust boot tool according to  claim 11 , wherein the piston further comprises an annular groove for receiving the second sealing ring. 
     
     
       13. The dust boot tool according to  claim 1 , wherein the shell further comprises:
 a regulator channel for receiving an air controller for connecting the inlet channel to the chamber or disconnecting the inlet channel from the chamber; 
 a first regulator aperture in communication with the regulator channel and the chamber; and 
 a second regulator aperture in communication with the regulator channel and the inlet channel. 
 
     
     
       14. The dust boot tool according to  claim 13 , wherein the air controller comprises:
 a trigger pivotally connected to the shell corresponding to an end of the regulator channel; 
 a sleeve comprising a tunnel and an aperture for connecting the tunnel to the first regulator aperture; 
 a collar comprising a bore made in an end and an axle formed at an opposite end, wherein the bore is located in the tunnel; 
 a cover connected to the shell to close an opposite end of the regulator channel and comprises a central aperture through which the axle extends; and 
 a valve rod comprising:
 an internal end inserted in the regulator channel and fitted in the bore of the collar; 
 an external end extending into contact with the trigger from the regulator channel; 
 an enlarged portion formed in the vicinity of the internal end of the valve rod; 
 at least one recess aligned with the second aligned with the second regulator aperture when the valve rod is in a selected position; 
 at least one sealing ring located around the valve rod in the vicinity of the external end; and 
 a second elastic element inserted in the bore and compressed between the enlarged portion and the collar to normally bias the recess from the second regulator aperture. 
 
 
     
     
       15. The dust boot tool according to  claim 14 , wherein the air controller further comprises a knob connected to the axle.